Owners and operators of video clients, players, and display devices often wish to maintain control over the content that is being displayed on these devices. Usually this is done by rating video as to content, differentially authorizing or not authorizing the content, and then restricting the playback of video media that has a non-authorized content rating.
Many different types of content rating exist. As one example, parents often desire to prevent their young children from being exposed to potentially disturbing video content which may have an unacceptably high violence or sexual content. As a result, one of the most common examples of content control is parental control of video content that is being played in a home setting.
To facilitate such parental control of video content, the Motion Picture Association of America (MPAA) has instituted a motion picture rating system that rates video content in terms of its level of appropriateness for children, adolescents, and adults. The MPAA content rating scheme rates video content as “G” (suitable for general audiences), PG (Parental Guidance Suggested), PG-13 (Parents strongly cautioned), R (Restricted, no children under 17 without a parent or guardian), and NC-17 (No Children 17 or under admitted). The actual MPAA rating mechanism is somewhat arbitrary and subjective, but generally sexually derived words, drug references, sexual content, and violence are associated with a more mature ratings.
In addition to parents, other groups and organizations occasionally desire to control video content as well. Corporations occasionally wish to restrict employee viewing to work related material. Sports team owners may occasionally wish to black out local broadcasts of sports games in order to improve gate sales. Plaintiffs may wish to block viewing video media containing libelous material. Copyright holders may wish to block viewing of illicitly copied material. At an extreme level of censorship a government may even wish to restrict a population from viewing material that contains political content that the government considers to be objectionable.
Depending on the target audience, the same video content can be produced in multiple versions, typically by removing portions of the video unsuitable for a certain rating category. It is common that a movie released on DVD or other read-only media has multiple versions with different ratings. The user can purchase the version with the rating he or she is interested in. This type of rating is fixed at the time of production and cannot be altered.
Existing methods of video content control included the “V-Chip” system. This system, which was originally introduced for analog television, relies upon a special “content rating” message that is embedded in the television program signal. In the case of analog TV, this rating message is transmitted in the vertical blanking interval between television frames. The V-chip detects this rating message, compares the rating message with the pre-set acceptability criteria programmed into the television (often by the parent that owns the television), and displays or blocks viewing of the program as appropriate. Thus, the same video content can be presented in different ways depending on the rating settings of the player.
One drawback of the V-chip system, and other similar content control systems, was that these systems relied on a video rating message that was transmitted along with the video media that was being viewed. The difficulty here is that most video media is unrated. Moreover, even if the video media is rated, the rating may not be appropriate for the needs of the particular user or organization. For example, a parent may have a high tolerance for violence but a low tolerance for sexual content, and thus may find the MPAA rating system inappropriate for his or her family. A copyright holder wishing to block access to unauthorized content will also find the V-chip and MPAA system to be inappropriate.
The viewer of media may also wish to employ automated content control methods. For example, a video viewer might prefer to delegate judgment as to what video media is or is not suitable for viewing to a non-official third party. For example, an intellectually inclined family might want to automatically delegate video content control to a third party organization that rates video as to intellectual content (i.e., a “consumer advocate” for video content). However, existing media control methods were incapable of allowing such flexible delegation methods.
An additional disadvantage of existing systems is that the rating information is embedded into the media content itself. This implies that legacy content not containing such information cannot be filtered by a player with content control capabilities. As a result of these and other deficiencies, existing video content control methods tended to be unsatisfactory, and tended to have limited market acceptance.